[Hummingbird Pro] Hummingbird – Combining files

Dear support,

Currently we are optimising a website and using Hummingbird for a couple or things. For example we are trying to combine .css files and .js files. As you can see on the website there are still multiple .css files and multiple .js files loaded instead of having them combined in one separate .js file and one separate .css file.

This should be possible right? Also it seems I cannot set “Combine” file for the app.css in the Hummingbird settings.

Is the above possible within Hummingbird?

I have enabled WPMU support.

Thanks in advance.
Justin